Why thin lines are blue?


Sorry maybe it’s a bit dumb question… But I’m reading books and see that almost all artists draw their first thin lines with the blue color… Why exactly blue and not green, orange, mm… grey for example?


Some scanners don’t see blue, or so they say. I have yet to see such a scanner, but anyway, my trad. 2D animation teacher said that you should use blue to sketch the things you’re sort of testing, and a regular pencil for the final thing.

I think it’s an animation thing.


I think Kargokullti is on the right track, I think the old Carbon Copy papers didnt see blue, so you wouldnt see the blue sketch lines if you carbon-copied your work.


Yeah. Before the age of computer graphics (I feel old), the fanciest tool available to us illustrators, designers, and animators was the Photocopier (a.k.a. Xerox machine). It let us scale small drawings big, cut and paste multiple images into one, and make multiples of our originals. And light blues were really hard to copy on those. It would copy them really faintly. This is what we old foggies took advantage of.


I’ve seen ppl sketch in different light colors now that the blue thing doesn’t make a difference. When you then finalize your drawing in black, your eye sees the black better. If I set my scanner to grayscale and I’ve sketched in light blue, the light blue is generally not picked up, or its converted to a really light gray.


In the “old days” artwork had to be photographed with film in order to be printed. One of the quirks of film is that it fails to capture that particular hue of blue. Film doesn’t come close to capturing all the colors we can see obviously, and this particular blue (sort of a cyan colored blue) doesn’t show up. It’s why the old film special effects used blue screens, as anywhere the blue was filmed, the negative would be clear allowing them to combine the first image with a second one easily. These days any color that can easily be seperated from the foreground image can be used (like a bright green which is common now) as it doesn’t depend on film so much as a computer just digitally erasing the color.


Adding to what Dweller said, before computer graphics, the graphics cameras used for producing the film required good, clean, black and white art. The camera “saw” light blue as white and red as black. So artists could put notes, instructions, layout lines, etc. in non-repro blue directly on the art. Artists would sketch the art in blue pencil and then go over it with black ink for their final art. The blue sketch lines were invisible to the camera.

Today, a scanner will pick up the blue line if scanning in grayscale. To simulate how old cameras worked, scan in black-and-white or bitmap mode.


to add to everyones posts… you can still buy a colerase called “non-photo blue” but its SUCKS, trust me its too light to be useful at all… blue and red are useful to give more of a range (so more screw-ups) before you get to black. when you DO get to black, blue likes to fade out of sight. if you use red, it is more visible than blue and adds a sort-of shadowy effect many artists like.

my favorite method of all is black prismacolor pencil on bienfang graphics 360 paper. its so smooth to draw on, and it will actually let you ERASE the waxy prisma lines like no other paper i know.


Thanks for an explanation!


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